Radial dependence of line profile variability in seven O9--B0.5 stars

Massive stars show a variety of spectral variability: presence of discrete absorption components in UV P-Cygni profiles, optical line profile variability, X-ray variability, radial velocity modulations. Our goal is to study the spectral variability of single OB stars to better understand the relation between photospheric and wind variability. For that, we rely on high spectral resolution, high signal-to-noise ratio optical spectra collected with the spectrograph NARVAL on the Telescope Bernard Lyot at Pic du Midi. We investigate the variability of twelve spectral lines by means of the Temporal Variance Spectrum (TVS). The selected lines probe the radial structure of the atmosphere, from the photosphere to the outer wind. We also perform a spectroscopic analysis with atmosphere models to derive the stellar and wind properties, and to constrain the formation region of the selected lines. We show that variability is observed in the wind lines of all bright giants and supergiants, on a daily timescale. Lines formed in the photosphere are sometimes variable, sometimes not. The dwarf stars do not show any sign of variability. If variability is observed on a daily timescale, it can also (but not always) be observed on hourly timescales, albeit with lower amplitude. There is a very clear correlation between amplitude of the variability and fraction of the line formed in the wind. Strong anti-correlations between the different part of the temporal variance spectrum are observed. Our results indicate that variability is stronger in lines formed in the wind. A link between photospheric and wind variability is not obvious from our study, since wind variability is observed whatever the level of photospheric variability. Different photospheric lines also show different degrees of variability.Comment: 13 pages, 9 figures + appendix. A&A accepted. Figures degraded for arxiv submissio

A MiMeS analysis of the magnetic field and circumstellar environment of the weak-wind O9 sub-giant star HD 57682

I will review our recent analysis of the magnetic properties of the O9IV star HD 57682, using spectropolarimetric observations obtained with ESPaDOnS at the Canada-France-Hawaii telescope within the context of the Magnetism in Massive Stars (MiMeS) Large Program. I discuss our most recent determination of the rotational period from longitudinal magnetic field measurements and Halpha variability - the latter obtained from over a decade's worth of professional and amateur spectroscopic observations. Lastly, I will report on our investigation of the magnetic field geometry and the effects of the field on the circumstellar environment.Comment: 2 pages, 2 figures, IAUS272 - Active OB Stars: Structure, Evolution, Mass Loss and Critical Limit

Organização da informação do Serviço de Atendimento ao Cidadão (SAC) para ações de transferência de tecnologias em duas unidades da Embrapa.

Aborda a importância da organização das informações para que uma empresa se torne inovadora, visualizando novos produtos, processos e serviços e mantendo-se aberta a mudanças constantes em sua gestão, no intuito de superar as transformações advindas de uma sociedade globalizada. Descreve o desenvolvimento de um sistema implantado com o objetivo de organizar as informações do Serviço de Atendimento ao Cidadão (SAC) em duas unidades da Embrapa, para nortear e otimizar futuras ações de transferência de tecnologias. Foram consideradas teorias que discutem a questão da dinâmica da modernidade e da globalização, como as de Baumann e Giddens, além da teoria sobre a organização da informação e do conhecimento em empresas, desenvolvida por Choo. Também são mencionadas algumas definições do processo de transferência de tecnologias e a importância dessas teorias para esse processo. A metodologia utilizada englobou alguns instrumentos, como a análise de Forças, Oportunidades, Fraquezas e ameaças (FOFA), o modelo de casos de uso e a análise de conteúdo. Apresentam-se os resultados atingidos na Embrapa Solos, ainda preliminares, mas que apontam melhorias significativas no processo de atendimento ao cidadão, como a possibilidade de fornecer perguntas e respostas a priori, o que diminuiu o número de perguntas repetidas mensais, evitando o retrabalho

Discovery of the first tau Sco analogues: HD 66665 and HD 63425

The B0.2 V magnetic star tau Sco stands out from the larger population of massive OB stars due to its high X-ray activity, peculiar wind diagnostics and highly complex magnetic field. This paper presents the discovery of the first two tau Sco analogues - HD 66665 and HD 63425, identified by the striking similarity of their UV spectra to that of tau Sco. ESPaDOnS spectropolarimetric observations were secured by the Magnetism in Massive Stars CFHT Large Program, in order to characterize the stellar and magnetic properties of these stars. CMFGEN modelling of optical ESPaDOnS spectra and archived IUE UV spectra showed that these stars have stellar parameters similar to those of tau Sco. A magnetic field of similar surface strength is found on both stars, reinforcing the connection between the presence of a magnetic field and wind peculiarities. However, additional phase-resolved observations will be required in order to assess the potential complexity of the magnetic fields, and verify if the wind anomalies are linked to this property.Comment: 6 pages, 2 tables, 3 figures. Accepted for publication in MNRAS. The definitive version will be available at www.blackwel-synergy.co